Kubernetes

For an overview of the available Kubernetes features and supported platforms, please see our Kubernetes guide.

This guide describes how to manage access to a Kubernetes cluster via the StrongDM Admin UI. This process involves creating and configuring a new cluster in the Admin UI and checking the connection to your Kubernetes API server.

If you would like to learn more about how to enable automatic resource discovery within your Kubernetes cluster, or use privilege levels to allow users to request various levels of access to the Kubernetes cluster, please read the Kubernetes Discovery and Privilege Levels section to learn more about those features prior to following this configuration guide.

Prerequisites

Ensure that the Kubernetes API server that you are adding to StrongDM is accessible from your StrongDM gateways or relays. See our guide on nodes for more information.

If you are using kubectl 1.30 or higher, it will default to using websockets, which the StrongDM client did not support prior to version 45.35.0. This can be remedied by taking one of the following actions:

• Update your client to version 45.35.0 or greater.

• Set the environment variable KUBECTL_REMOTE_COMMAND_WEBSOCKETS=false to restore the previous behavior in your kubectl.

Add Your Kubernetes Cluster in the StrongDM Admin UI

1. Log in to the Admin UI and go to Infrastructure > Clusters.

2. Click the Add cluster button.

3. Select Kubernetes as the Server Type and set other resource properties to configure how the StrongDM relay connects.

4. Click Create to save the resource.

The Admin UI updates and shows your new cluster in a green or yellow state. Green indicates a successful connection. If it is yellow, click the pencil icon to the right of the server to reopen the Connection Details screen. Then click Diagnostics to determine where the connection is failing.

Your gateways or relays must be able to connect to the entry you choose for the hostname. To verify the connection, use the command prompt from the gateway or relay server and type nc -z <HOSTNAME> port. If your server can connect to this hostname, you can proceed.

Resource properties

Configuration properties are visible when you add a Cluster Type or when you click to view the cluster's settings. The following table describes the settings available for your Kubernetes cluster.

Property	Requirement	Description
Display Name	Required	Meaningful name to display the resource throughout StrongDM; exclude special characters like quotes (") or angle brackets (< or >)
Cluster Type	Required	Select Kubernetes
Proxy Cluster	Required	Defaults to "None (use gateways)"; if using proxy clusters, select the appropriate cluster to proxy traffic to this resource
Hostname	Required	Hostname or IP address of the Kubernetes API server, such as api.kubernetes.example.com; relay server should be able to connect to your Kubernetes API server
Port	Required	Port to connect to the API server; default port value 443
Connectivity Mode	Required	Select either Virtual Networking Mode, which lets users connect to the resource with a software-defined, IP-based network; or Loopback Mode, which allows users to connect to the resource using the local loopback adapter in their operating system; this field is shown if Virtual Networking Mode enabled for your organization
IP Address	Optional	If Virtual Networking Mode is the selected connectivity mode, an IP address value in the configured Virtual Networking Mode subnet in the organization network settings; if Loopback Mode is the selected connectivity mode, an IP address value in the configured Loopback IP range in the organization network settings (by default, 127.0.0.1); if not specified, an available IP address in the configured IP address space for the selected connectivity mode will be automatically assigned; this field is shown if Virtual Networking Mode and/or multi-loopback mode is enabled for your organization
Port Override	Optional	If Virtual Networking Mode is the selected connectivity mode, a port value between 1 and 65535 that is not already in use by another resource with the same IP address; if Loopback Mode is the selected connectivity mode, a port value between 1024 to 64999 that is not already in use by another resource with the same IP address; when left empty with Virtual Networking Mode, the system assigns the default port to this resource; when left empty for Loopback Mode, an available port that is not already in use by another resource is assigned; preferred port also can be modified later from the Port Overrides settings
DNS	Optional	If Virtual Networking Mode is the selected connectivity mode, a unique hostname alias for this resource; when set, causes the desktop app to display this resource's human-readable DNS name (for example, k8s.my-organization-name) instead of the bind address that includes IP address and port (for example, 100.64.100.100:5432)
Secret Store	Optional	Credential store location; defaults to Strong Vault; to learn more, see Secret Store options
Server CA	Optional	Pasted server certificate (plaintext or Base64-encoded), or imported PEM file; you can either generate the server certificate on the API server or get it in Base64 format from your existing Kubernetes configuration (kubeconfig) file
Client Certificate	Optional	Pasted client certificate (plaintext or Base64-encoded), or imported PEM file; you can either generate the client certificate on the API server or get it in Base64 format from your existing Kubernetes configuration (kubeconfig) file
Client Key	Optional	Pasted client key (plaintext or Base64-encoded) or imported PEM file; you can either generate the client key on the API server or get it in Base64 format from your existing Kubernetes configuration (kubeconfig) file
Healthcheck Namespace	Optional	If enabled for your organization, the namespace used for the resource healthcheck; defaults to default if empty; supplied credentials must have the rights to perform one of the following kubectl commands in the specified namespace: get pods, get deployments, or describe namespace
Enable Resource Discovery	Optional	Enables automatic discovery within this cluster
Authentication	Required	Authentication method to access the cluster; select either Leased Credential (default) or Identity Aliases (to use the Identity Aliases of StrongDM users to access the cluster)
Identity Set	Required	Displays if Authentication is set to Identity Aliases; select an Identity Set name from the list
Healthcheck Username	Required	If Authentication is set to Identity Aliases, the username that should be used to verify StrongDM's connection to it; username must already exist on the target cluster
Resource Tags	Optional	Resource Tags consisting of key-value pairs <KEY>=<VALUE> (for example, env=dev)

Display name

Some Kubernetes management interfaces, such as Visual Studio Code, do not function properly with cluster names containing spaces. If you run into problems, please choose a Display Name without spaces.

Client credentials

When your users connect to this cluster via StrongDM, they have exactly the same rights as the user associated with these keys. Make sure to consider this prior to setup.

Server CA

How to get the Server CA from your kubeconfig file:

1. Open the CLI and type cat ~/.kube/config to view the contents of the file.

2. In the file, under - cluster, copy the certificate-authority-data value. That is the server certificate in Base64 encoding.

  - cluster:
    certificate-authority-data: ... SERVER CERT BASE64 ...

Client certificate

How to get the Client Certificate from your kubeconfig file:

1. From the CLI, type cat ~/.kube/config to view the contents of the file.

2. In the file, under - name, copy the client-certificate-data value. That is the client certificate in Base64 encoding.

  - name: clusterUser_StrongDM_example
    user:
    client-certificate-data: ... CLIENT CERT BASE64...

Client key

How to get the Client Key from your kubeconfig file:

1. Open the CLI and type cat ~/.kube/config to view the file.

2. In the file, under - name, copy the client-key-data value. That is the client private key in Base64 encoding.

  - name: clusterUser_StrongDM_example
    user:
    client-key-data: ... CLIENT PRIVATE KEY BASE64...

Secret Store

By default, server credentials are stored in StrongDM. However, these credentials can also be saved in a secrets management tool.

Non-StrongDM options appear in the Secret Store dropdown if they are created under Settings > Secrets Management. When you select another Secret Store type, its unique properties display. For more details, see Configure Secret Store Integrations.